The demographics of the most popular social networking sites are changing quickly and, once again, the team at Flowtown has done a great job of compiling the latest statistics about Facebook users and social network usage in general. Did you know that the average age of a Facebook user is 38 years old? Even more interesting is that 61% of Facebook users are now older than 38 — the company has come a long way since first launching exclusively to an audience of college students.

And what about Twitter? The average Twitter user is 39, and 64% of tweeters are 35 or older.

Another interesting statistic found in the data is that social media users who are 18 to 29 use social networks almost as much as they use e-mail; other reports have recently suggested that users under 18 use social networks more than e-mail.

Social networks worldwide will rake in $3.3 billion in advertising dollars this year, according to updated estimates by eMarketer. That’s a 31% increase from 2009′s $2.5 billion. And Facebook is the biggest winner — 39% of that amount, or $1.3 billion, will go to the social-media juggernaut.

In the U.S., social ad spending is expected to rise 20% to $1.7 billion and Facebook has an even larger market share — 50 percent of that amount ($835 million), versus a 36% share last year (when its U.S. advertising revenues were estimated to be $500 million out of a total of $1.4 billion).

The big loser in social ads this year? MySpace, whose share is estimated to drop from 32% in 2009 ($445 million) to 19% in 2010 ($323 million).

Online social games and applications are becoming a more important part of the mix. Advertising is not a primary revenue stream for game companies like Zynga or Playdom, but their large audiences are interesting to marketers. eMarketer expects companies like these to attract $293 million in spending worldwide in 2011, up from $220 million in 2010.

Twitter, which finally launched its ad business earlier this year, is part of eMarketer’s forecast for the first time. Although worldwide ad spending on Twitter will be under $50 million in 2010, the potential for 2011 and beyond could be dramatic if its “resonance” model of measuring advertising effectiveness works.

Here’s a nice infographic from Flowtown that does a great job of summarizing all of eMarketer’s data:

Pew has just released the latest results from its Internet and American Life Project survey, which found that the fastest growing demographic adopting social media is people over 50.

All age groups continue to jump on the social networking bandwagon, and young adults still dominate. But social media use among Internet users ages 50 and older has nearly doubled — from 22% in April 2009 to 42% in May 2010. In the 50- to 64-year-old bracket, the figure leaped from 25% to 47%, and for those over 65 the figure shot up from 13% of the population using social nets to 26%. By way of comparison, 76% of users 18 to 29 used social nets in 2009 and this group’s usage rose to 86% this year.

“Young adults continue to be the heaviest users of social media, but their growth pales in comparison with recent gains made by older users,” explains Mary Madden, Senior Research Specialist and the report’s author. “E-mail is still the primary way that older users maintain contact with friends, families, and colleagues, but many older users now rely on social network platforms to help manage their daily communications.”

Other data from the survey of 2,200 American adults revealed growing interest among older users in social status sites like Twitter: 11% of them now have used Twitter or a similar site this year, versus just 5% last year — and 6% of them do so on a daily basis, compared to just 1% in 2009. Here’s some interesting info about how various age groups leverage various social platforms on a daily basis:

Pew doesn’t analyze the reasoning behind the upward trend of social media usage by older adults, but it’s likely that it’s partly a natural progression — adoption of new technology is propagating up through the age groups, similar to the “silver surfer” phenomenon described among British users. And services like Facebook and Twitter are expanding the scope of their platforms as business-to-consumer branding, promotional, and contact management tools.

Edison Research just released its latest report on social network usage. The study compares the behavior and demographics of frequent users of social media to those of the population at large. The data is based on a nationally representative telephone survey of 1,753 Americans (including 371 mobile phone interviews) ages 12+ conducted in February, 2010.

Here are the principal findings from the report:

1. With both usage of social networks and the frequency of that usage increasing dramatically, we are truly witnessing a sea change in how mainstream consumers communicate.

2. Though social networking is rapidly becoming more common throughout the wider population, it is still most popular among the young; students are especially overrepresented.

3. Women are bigger social media users than men.

4. The biggest social networkers are, unsurprisingly, more likely to be big Internet users and early-adopters of new gadgets. But they still think the mobile phone is the technology that has had the biggest impact on their lives.

5. Frequent social networkers are also more likely to update their status on those networks — i.e., create content online — which has implications for word-of-mouth marketing and search.

6. Not only are frequent social networkers posting more status updates, they are also more likely to follow brands/companies than the average social media user — which makes identifying and appealing to those with the “social habit” crucial for brands.

7. Mobile access to social media is almost certainly a significant contributor to frequency of usage.

8. The data for frequent social networkers’ usage of podcasts, online video, and online audio supports the assumption that a significant amount of content is being consumed on-demand, potentially at the point where such content is shared.

9. Americans with “the social habit” are watching significantly less traditional television, but potentially consuming (and sharing) more “video” through alternative means.

Back in March 2008, Facebook was poised to overtake MySpace, but it wasn’t yet the most popular social network in the world. Now it’s obliterating everybody. This chart from a report on SharesPost tells the story: Facebook’s popularity is unmatched — it’s on a completely different scale than its competitors.

And Facebook’s advertising business is booming thanks to brands marketing their Facebook pages (and spamming their customers like they used to in the good old days via e-mail) and virtual game studios’ steady acquisition of new users. There’s also “Pay With Facebook”, which gives Facebook a 30% cut of its insanely fast-growing virtual goods market AND could wind up us a one-click payment option across the Internet.

About 127 million Americans, or three-quarters of the population, use social media, according to Nielsen Online. In a survey of 1,700 Internet users, researchers found that 73% engage in social media at least once a week. Engagement was defined as reading a blog, visiting a social network, or reading/commenting on a message board.

The Nielsen study, commissioned by women-focused blog network BlogHer and NBCU’s iVillage, found that Facebook is becoming a major attraction for a majority of the population, rivaling the reach of traditional media channels. Of the online population, 47% visit Facebook daily, according to Nielsen, nearly rivaling the 55% that watch TV. Facebook daily use easily beats out other traditional media like radio (37%) and newspapers (22%).

Social gaming is a daily habit for a huge number of people. According to Nielsen’s survey, 32.7 million people play social games daily. That’s equivalent to newspaper readership and more than double the readership of magazines in the sample. Social games are polarizing, however, as over 50% said they never play them.

For all its buzz, the study found Twitter is still a niche activity for all but a small segment of the online population. Twitter boasts 105 million registered users — but according to Nielsen, just 11.4 million (6%) use it daily.

BlogHer and iVillage commissioned the research to determine the role of social media in the lives of women versus the general population. It found little differences between the sexes when it comes to social media adoption, with women slightly more likely to tweet and blog while men watch more videos.

Blog reading remains a niche activity for online users, with just 11% saying they read them daily — it trailed message board readers (17%). BlogHer’s audience, of course, is more inclined to visiting blogs as a habit, with 77% reading them daily and 96% weekly. The BlogHer audience sample also identified blogs as trailing only search among ad-supported media in purchasing decisions.

BlogHer COO Elisa Camahort said the popularity of social networking is not stealing time and attention from blogs. “It’s like any media progress we’ve had,” she said. “Nothing is killing the other media source. Blogs are still where substantive conversations are happening. It’s not on Facebook.”

More and more professionals are using social networks to build relationships, meet new contacts, and market themselves and their businesses. But diving into the virtual meet-and-greet can be daunting. Where to begin?

The answer is LinkedIn, a social network for professionals who are looking to promote both themselves and their companies. Developed specifically for business, you don’t run the risk of blurring your professional life with your private one. LinkedIn offers an amazing opportunity to generate new leads — you can find, be introduced to, and collaborate with qualified professionals who can help you accomplish your goals and grow your business.

LinkedIn has great tools for connecting you to customers, prospects, and industry thought leaders alike, and many marketers are under-utilizing its functionality due to simple lack of awareness — joining LinkedIn is simple, but turning it into a powerful networking tool takes a bit of know-how.

Some LinkedIn facts

The site has over 60 million members

A new member joins approximately every second

Executives from all Fortune 500 companies are members

Benefits of a complete and well-developed LinkedIn presence

Excellent source of SEO-friendly links: LinkedIn has great authority in Google; and you can can create unique anchor text for your Web site links, which are given the dofollow attribute (LinkedIn’s PageRank is 9).

How to get going with LinkedIn

If you don’t already have a personal profile on LinkedIn, here are some simple steps you can follow to set one up:

1. Create a complete personal profile

When you interact with others on LinkedIn, your profile is the first thing they see so it needs to be complete. Make sure you fill in all relevant information about yourself, your areas of expertise, and your experience — visit the site’s main page to get started.

Upload a professional photo of yourself. Profiles with photos are more credible, so people are more likely to engage with you.

The more optimized your profile is, the more relevant it will be in search results. Use some basic SEO techniques, including hyperlinking targeted keywords. When you post the URLs for your company and your blog, make sure you customize them — for example, instead of using the default anchor text for linking to your blog (“My Blog”), change it to your blog’s actual title (“Pamorama” in my case).

Use keywords in descriptions. Make your profile more search-friendly by including your keywords in your summary, specialties, and experience.

Your profile is not complete if you don’t have some recommendations. You can ask for a recommendation from previous employers, your current employer, or other business contacts. Getting recommended is important because it adds to your credibility — it demonstrates that your expertise is valued by people who have actually worked with you.

3. Build a strong network of contacts

Now you need to start adding connections. Make sure you connect to friends and colleagues — LinkedIn makes this easy for you by looking in your e-mail address book to find contacts who are already on the network. You can also use the search box on the top right to look for people you know:

Encourage every employee to have a LinkedIn profile and to link to each other. Extending your network in this way increases your exposure outside your company.

Once you’re connected to colleagues and friends, you can browse their networks, find potential prospects and ask your connections for an introduction, or simply contact the decision-makers in these businesses directly. You can also find people who are considered authorities in your industry and try to get in touch with them.

4. Use third-party applications to make the most of your profile and promote your company

There are many third-party applications on LinkedIn that can help you effectively promote yourself, your company, your Web site, and your blog. You can use SlideShare so visitors can see your business presentations, Company Buzz to monitor what’s being said about your company on Twitter, or Box.net to upload and manage files. And the aptly named Tweets displays your most recent Twitter updates.

With the WordPress application, you can synchronize your blog with your profile and display your most recent posts with summaries — updates are automatically sent to your network when you write new content:

5. Promote your personal profile

You can promote your profile on LinkedIn itself and via other means. On LinkedIn, users see a link to your profile wherever you participate (in groups, discussions, etc.), so the more you interact the more exposure you’ll receive. You can also post your profile URL on your Web site, your blog, your business card, in your e-mail signature, on any other social networking sites you use — anywhere you provide information about yourself.

6. Engage with other users

The more you actively engage and provide valuable contributions, the more you’ll be appreciated in the community. Make sure you participate in discussions, ask and answer questions, and update your status on a regular basis.

7. Keep your profile up to date

It seems obvious, but many people create a profile and then let it languish. Updating relevant information on a regular basis is essential for credibility.

Establish your company’s presence

Now that you’ve created your own presence on LinkedIn, it’s time to do the same for your company:

1. Create your company’s profile

To get started, go to the “Companies” menu on LinkedIn. From there, select “Add Company”.

Follow LinkedIn’s wizard and enter basic information about your company, like its description, number of employees, and industry it operates in — you’ll be able to add a logo, locations, and a feed for your company blog. As with your personal profile, make your company profile more search-friendly by including your keywords in its description.

In addition to showing off the basic information you provided, LinkedIn will pull in data about your company from around the site. So, for example, all of your job listings will automatically show up on your profile, along with links to the profiles of all current employees, former employees, new hires, and recent promotions. LinkedIn also does analysis of your company and the connections that your employees have on the network. For example, it will automatically calculate your employees’ median age, top schools, and determine other companies that they are well-connected to.

All of this aggregate data about your company gives potential customers, partners, and anyone else who’s interested in your company a lot of information to dive into and help determine if it might be a good fit for them. And for you, once it’s set up, it all happens automatically as you and your employees use LinkedIn. Make it a point to edit your company’s basic profile information as necessary to keep it up to date.

If you’re interested in leveraging the network for recruiting, LinkedIn offers a premium product called Custom Company Profiles that lets you add more features, like videos about your company and positions, interactive polls, and other recruiting-specific customizations. These are worth considering for larger companies (they’re pricey), but for small businesses, a basic LinkedIn company profile should be enough to create a brand on the site.

2. Promote your company’s profile

Use the same methods to promote your company’s profile as you do for your personal one — on LinkedIn, point people to your company profile link when you participate in discussions and ask questions. In other places, post your company profile URL on your Web site, your blog, your business card, in your e-mail signature, etc.

3. Develop relationships with key business partners or media contacts

When you search for someone on LinkedIn, you can be very precise about who you want to reach. So, for example, if you know that your business needs to expand into the smartphone market, you can start targeting and reaching out to companies like Apple, Research In Motion, and HTC. If you want to increase your visibility, start reaching out to media members who cover your industry.

4. Start a group

Demonstrate your willingness to share information about your industry or niche by creating a group:

Here are some suggestions to get it started right:

Choose a relevant name. The name of your group should contain keywords so it can be found by people interested in your industry.

Add a logo. In the same sense that a photo is important for your personal profile, a good logo helps with branding.

Use the available option to display your group in the Group Directory and on member’s profile.

5. Promote and manage your group

Creating a group and then abandoning it won’t help you — you need to promote it and manage it. In order to get members, you need to promote your group — start by inviting your connections who might be interested in your industry, but don’t limit the group to your connections. And keep members engaged by starting discussions and posting interesting news, sending announcements, importing your blog’s RSS feed, etc.

Group promotion tips:

Send e-mail to your customers to introduce them to your group and invite them to participate

Add the group’s logo to your Web site or blog and link it back to the group itself

Promote the group on other social social networking sites

Do you use LinkedIn to market your business? Please share your experience!